<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <!-- 
    1. 安装工具 babel-cli babel-preset-env browserify(webpack)

      npm init -y
      生成package.json

      然后才能安装工具
      npm i babel-cli babel-preset-env browserify -D

    2. 转换ES
      npx babel src/js -d dist/js --presets=babel-preset-env

    3. 打包 npx browserify dist/js/app.js -o dist/bundle.js
   -->
</body>
<script src="./dist/bundle.js"></script>

</html>